Charlize Theron reveals how her extreme weight gain for 'Tully' led to depression

Packing on the pounds for a movie role isn’t nearly as enjoyable as you would think.

Charlize Theron told Yahoo Entertainment that she added 50 pounds (clarifying earlier reports that it was “only” 35) for her latest role in Tully, the new Diablo Cody-scripted, Jason Reitman-directed drama about a working-class mother who, after struggling with the arrival of a third child, reluctantly accepts the aid of a night nurse (Mackenzie Davis) from her wealthy brother (Mark Duplass).

“It’s fun for about three weeks, then it’s not so fun anymore,” Theron told us of her extreme weight gain (watch above).

Not only did the Monster Oscar winner struggle with her latest physical transformation, it also affected her emotional health.

“Eating like that, I dealt with depression for the first time in my life,” she said. “I’d never experienced anything like that.”

As for how she put on the weight?

“I was drinking a lot of sugar and eating a lot of processed foods. And my body just kind of gave up on me halfway through.”